An internal combustion engine requires clean, filtered air to meet current efficiency and durability requirements. A variety of filtration devices are used to remove particulate contaminants, including dust particles, mists, smoke particles, and the like from air entering the engine.
Typically, filtration devices include a filtering media disposed inside a housing. A fluid such as air, for example, flows into the housing and through the filtering media. As the fluid passes through the filtering media, particulate contaminants are removed therefrom. After passing through the filtering media, the fluid flows out of the housing and to a desired location, such as an automobile engine, for example.
It is desirable to produce filtering media having a maximized filtration capacity and efficiency and a minimized flow restriction of the fluid flowing therethrough. U.S. Pat. No. 4,118,161 discloses a manufacturing process for rigidized convoluted foam, wherein the resultant product could be used as an air filter. The manufacturing process to rigidize the foam involves nesting a plurality of convoluted foam sheets and thereafter impregnating the foam sheets with a mixture of a thermosetting melamine, urea, or benzoguanamine resin and a cross-linker. After the resin mixture has reacted, the nested foam sheets are separated. Each unnested sheet could be used as a convoluted, self-standing air filter.
It would be desirable to produce a filtration device for an internal combustion engine which could be simply and inexpensively manufactured and installed, wherein a flow restriction caused by the filter media is minimized and a capacity and an efficiency thereof are maximized.